Adhesive for energy conversion and storage devices

Abstract

Described herein are electrode active layers for energy conversion or storage devices, such as supercapacitors or batteries, comprising an active material and a binder comprising a salt of a sulfonated polymer. Also described herein are slurries for producing such active layers, composite electrodes comprising such active layers, as well as the use of such active layers in energy conversion or storage devices, and methods of making such active layers.

Description

Technical Field

[0001] The present invention relates to adhesives used in energy conversion and storage devices. In particular, the present invention relates to polymeric materials containing ionized charged functional groups that serve as adhesives. The adhesives herein can be used to provide improved performance in energy conversion and storage devices such as supercapacitors, but the present invention is not limited to this particular use. Background Art

[0002] Any discussion of the prior art throughout this specification should in no way be taken as an admission that such prior art is widely known or forms part of the common general knowledge in the art.

[0003] Energy conversion and storage devices are widely used in various electrical appliances and applications. Capacitors are one such device and are capable of rapid, high-power delivery of energy, but the amount of energy delivered is very small (i.e., they have low capacitance). Batteries are another device and store a much larger amount of energy than capacitors, but at the expense of design to achieve functionally adequate power delivery. In terms of energy and power, supercapacitors lie between these devices and are generally capable of rapidly, high-power delivering a relatively large amount of energy.

[0004] Supercapacitors (also known as ultracapacitors) can be generally classified as electric double layer capacitors (EDLCs), pseudocapacitors, or hybrid capacitors. EDLCs store energy by separating static charges, pseudocapacitors (also known as electrochemical capacitors) store energy through redox processes but have the charge-discharge characteristics of capacitors, and hybrid capacitors store energy in a mixed manner of redox and static charges. Like batteries, supercapacitors typically include two opposing electrodes electrically isolated by an intermediate electron-insulating separator that is porous and permeated by an electrolyte. Two current collector terminals are usually connected to and extend from the respective electrodes to allow access to the electrodes from the outside, and the entire cell is sealed in a package to prevent the entry of water and air and the outflow of the electrolyte.

[0005] The capacitance, or the ability to store an electric charge, is proportional to the overlapping area of the charged plates and inversely proportional to the distance between the plates. Thus, the performance of a capacitor using conventional materials is limited by its size. To overcome this problem, the present applicant has disclosed supercapacitor devices that overcome the size problem by using carbon with an extremely high surface area as the plate coating material; see WO 98 / 054739, WO 99 / 053510, WO 00 / 016352, WO 00 / 034964, WO 01 / 004920, WO01 / 089058, and WO 12 / 151618, the respective contents of which are incorporated herein by reference. The electrode consists of a metal current collector, a coating material typically formed of particulate carbon, and an adhesive that serves to adhere the carbon to itself and the associated current collector. The coated electrodes are separated by a separator, stacked or wound together, and disposed within a housing containing an electrolyte.

[0006] The power performance of a supercapacitor is strongly affected by the internal resistance or equivalent series resistance (ESR) of the device, where the lower the ESR of the device, the better the power performance. The ESR is the sum of the resistances of all materials (e.g., current collector, active material, adhesive, separator, electrolyte, and all internal and external contact resistances).

[0007] As a component of the overall system, the adhesive used in a supercapacitor affects the ESR and thus the device performance. An adhesive is a chemical that provides cohesive strength to hold together the materials that make up the electrode active layer, provides adhesive strength to hold the electrode active layer on the current collector, and provides an electrical connection means for charging and discharging the electrode. An ideal adhesive should interfere as little as possible with the function of the materials in the electrode active layer while still providing the necessary cohesive and adhesive functions. The adhesive may also need to be flexible so that the electrode active layer is not adversely affected by mechanical stresses (e.g., bending or vibration) that the device may experience during its operating life. Typical adhesives used in the art include carboxymethyl cellulose (CMC), styrene butadiene (SBR), polytetrafluoroethylene (PTFE), poly(vinylidene fluoride) (PVDF), poly(tetrafluoroethylene), polyvinyl fluoride, ethylene-propylene-diene copolymer, and styrene-butadiene rubber, or their copolymers and / or variants. Many of the adhesives used in supercapacitors also serve as adhesives for battery electrodes.

[0008] Typically, a binder is mixed with the materials constituting the electrode active layer in a liquid carrier (such as water or an organic solvent), and then the resulting slurry or suspension is coated on a substrate and dried to expel the liquid carrier.

[0009] Due to environmental concerns, there is a great demand for binders compatible with aqueous coating processes. CMC, polyacrylic acid (PAA), or polyvinyl alcohol (PVA) are all compatible with aqueous processing, but have the following disadvantages, for example, they contain reactive hydroxyl groups (which reduce stability and cause gas formation), contain impurities (such as chlorides) and / or have poor dispersant quality. Other water-dispersible binders in the form of latex particles (such as SBR, PTFE, and PVDF) require dispersants to stabilize the latex particles, which reduces the performance of the equipment and usually requires the addition of adhesion promoters. These problems related to binders in supercapacitors also apply to battery energy storage applications.

[0010] With the development of the field of energy conversion and storage devices and the improvement of application requirements, there is an increasing demand for new components (including binders) that exhibit better stability and operating characteristics (including improved ESR performance) and / or are compatible with environmentally friendly processing methods.

[0011] The object of the present invention is to overcome or improve one or more disadvantages of the prior art, or at least provide a useful alternative. Summary of the Invention

[0012] According to a first aspect of the present invention, there is provided an electrode active layer for an energy conversion or storage device, comprising: an active material; and a binder comprising a salt of a sulfonated polymer.

[0013] According to the above first aspect, the following features may be used alone or in any suitable combination.

[0014] The sulfonated polymer may include substituted C2 to C6 linear or branched olefin monomers. The substituted C2 to C6 linear or branched olefin monomers may include one or more of the following as substituents: -R1SO3 - , -R1ArSO3 - , -ArR1SO3 - , -ArSO3 - or -C(=O)NHR1SO3 - , -C(=O)NHR1ArSO3 - , -C(=O)NHArR1SO3 - ; where R1 = C1 to C6 linear or branched alkyl or a bond; and Ar = aryl. Ar may be phenyl. The sulfonated polymer may include benzenesulfonic acid groups.

[0015] The sulfonated polymer may include monomers, each monomer including a sulfonate group. In some embodiments, the sulfonated polymer includes monomers, each monomer containing a benzenesulfonic acid group. The sulfonated polymer may include one or more monomers selected from the following: styrene sulfonate, vinylsulfonate, 2-acrylamido-2-methyl-1-propanesulfonate, 2-propene-1-sulfonate, or 2-methyl-2-propene-1-sulfonate. In one embodiment, the monomer is styrene sulfonate.

[0016] The salt of the sulfonated polymer may include one or more counterions selected from the following: Group I metal cations, Group II metal cations, transition metal cations, quaternary ammonium cations, or nitrogen-containing heterocyclic cations. The salt of the sulfonated polymer may include one or more counterions selected from lithium cations, potassium cations, sodium cations, cesium cations, magnesium cations, and calcium cations.

[0017] The salt of the sulfonated polymer may include one or more counterions selected from the following: optionally substituted alkylammonium cations such as tetramethylammonium, tetraethylammonium, tetrapropylammonium, or tetrabutylammonium, or 2-(methylthio)ethylammonium cations; or nitrogen-containing heterocyclic cations such as spiro-bis-pyrrolidinium (SBP), N,N-dimethylpyrrolidinium, N-methyl-N'-propylpyrrolidinium, N,N'-dimethylimidazolium, N-methyl-N'-ethylimidazolium, or N-methyl-N'-propylimidazolium.

[0018] The sulfonated polymer may have an average molecular weight of about 20,000 g / mol to about 2,000,000 g / mol. In one embodiment, the sulfonated polymer has an average molecular weight of about 20,000 g / mol to about 1,000,000 g / mol. In one embodiment, the sulfonated copolymer has an average molecular weight of about 20,000 g / mol to about 2,000,000 g / mol.

[0019] The binder may include at least 30 wt% of the salt of the sulfonated polymer. In one embodiment, the binder includes at least 50 wt% of the salt of the sulfonated polymer. In one embodiment, the binder includes at least 90 wt% of the salt of the sulfonated polymer.

[0020] The sulfonic acid polymer can be a copolymer comprising two or more different sulfonated monomers, or can be a copolymer comprising one or more sulfonated monomers and at least one other monomer, wherein the sulfonated monomer comprises: one sulfonic acid group per monomer, optionally one benzenesulfonic acid group per monomer, and wherein at least one other monomer has no sulfonic acid group, optionally wherein at least one other monomer is selected from one or more of the following: 1,2-difluoroethylene, tetrafluoroethylene, styrene, butadiene, maleic anhydride, maleic acid or its salts, acrylic acid or its salts, methacrylic acid or its salts, or butylacrylic acid or its salts.

[0021] The binder can comprise a mixture of salts of two or more different sulfonated polymers, or can comprise a mixture of a salt of a sulfonated polymer and at least one other polymer. The other polymer can be selected from PVDF, PTFE, SBR, or acrylic-based polymers. The active material can be amorphous carbon, such as activated carbon.

[0022] The electrode active layer can further comprise a conductive material, such as conductive carbon.

[0023] According to a second aspect of the present invention, there is provided a composite electrode comprising: the electrode active layer of the first aspect as described above on a conductive surface.

[0024] According to a third aspect of the present invention, there is provided an energy storage device comprising the composite electrode according to the second aspect above. The energy storage device can be a supercapacitor, or can be a battery. Thus, there is provided herein a supercapacitor comprising the composite electrode according to the second aspect above. There is also provided herein a battery comprising the composite electrode according to the second aspect above.

[0025] According to a fourth aspect of the present invention, there is provided the use of a salt of a sulfonated polymer as a binder in an electrode active layer of a composite electrode.

[0026] According to a fifth aspect of the present invention, there is provided an electrode paste for producing an electrode active layer, the electrode paste comprising: an active material; a binder comprising a salt of a sulfonated polymer; and a solvent.

[0027] According to the fifth aspect above, the following features can be used individually or in any suitable combination.

[0028] The electrode paste can comprise 50 wt% to 95 wt% of a solvent. The solvent can be water. The electrode paste can comprise 1 wt% to 30 wt%, such as 2 wt% to 20 wt% based on solids, of a binder. The paste can be a substantially homogeneous dispersion of the active material.

[0029] According to a sixth aspect of the present invention, there is provided a method for manufacturing an electrode active layer, comprising: applying the electrode paste according to the above fifth aspect to a current collector; and drying the electrode paste to remove the solvent.

[0030] Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprising", "including", etc. shall be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is, in the sense of "including but not limited to".

[0031] It should be understood that any numerical range cited herein is intended to include all sub-ranges subsumed therein. For example, a range of "x to y" or "between x and y" is intended to include all sub-ranges between x and y as well as the range endpoints x and y.

[0032] As used herein, the singular forms "a", "an" and "the" may refer to plural articles unless specifically stated otherwise. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0034] Figure 1 Shows the ESR rise rate over time of a supercapacitor having an electrode containing a sodium polystyrene sulfonate polymer (MW = 100,000 g / mol) binder according to an embodiment of the present invention, compared to the ESR rise rate of an equivalent supercapacitor containing a conventional CMC binder;

[0035] Figure 2 Shows compared to Figure 1 The capacitance rise rate over time of the same supercapacitor;

[0036] Figure 3 Shows compared to Figure 1 The frequency response of the capacitance of the same supercapacitor (Bode magnitude plot);

[0037] Figure 4 Shows compared to Figure 1 The Bode phase plot of the same supercapacitor;

[0038] Figure 5 Shows compared to Figure 1 The internal pressure of the same supercapacitor;

[0039] Figure 6 Shows compared to Figure 1The ESR rise rate over time of a supercapacitor with an electrode containing a sodium polystyrene sulfonate polymer (MW = 70,000 g / mol) binder according to an embodiment of the present invention, compared to the ESR rise rate of the PSS supercapacitor in

[0040] Figure 7 shows the capacitance rise rate over time of the Figure 6 same supercapacitor;

[0041] Figure 8 shows the ESR rise rate over time of a supercapacitor with an electrode containing a polystyrene sulfonic acid polymer (MW = 75,000 g / mol) binder having Ca or Mg counterions according to certain embodiments of the present invention;

[0042] Fig. 9 shows the capacitance rise rate over time of the Figure 8 same supercapacitor;

[0043] Fig.10 shows the ESR rise rate over time of a supercapacitor with an electrode containing a polystyrene sulfonic acid polymer (MW = 75,000 g / mol) binder having Li, K, or Cs counterions according to certain embodiments of the present invention;

[0044] Fig.11 shows the capacitance rise rate over time of the Fig.10 same supercapacitor;

[0045] Fig.12 shows the capacitance rise rate over time of an asymmetric supercapacitor containing an electrode with a polystyrene sulfonic acid polymer binder according to an embodiment of the present invention and an electrode with a conventional binder SBR;

[0046] Fig.13 shows the ESR rise rate over time of the Fig.12 same supercapacitor;

[0047] Fig.14 shows the Fig.12 EIS Nyquist plot of the same supercapacitor;

[0048] Fig.15 shows the Fig.12 Bode phase plot of the same supercapacitor;

[0049] Fig.16 shows the Fig.12 EIS resistance Bode plot of the same supercapacitor;

[0050] Fig.17 shows the EIS capacitance Bode plot of the same supercapacitor; Fig.12

[0051] Fig.18 shows the rate of increase of ESR over time of a supercapacitor containing an electrode according to certain embodiments of the present invention, the electrode including a polystyrene sulfonic acid - maleic acid copolymer (MW = 20,000 g / mol) binder; and

[0052] Fig.19 shows the rate of increase of capacitance over time of the same supercapacitor. Fig.18 DETAILED DESCRIPTION

[0053] The invention described herein relates to a binder comprising a polymeric material containing a sulfonate functional group, which binder is used as a component in an electrode active layer of an energy conversion and storage device. More specifically, the disclosure herein encompasses an electrode active layer for an energy conversion or storage device, which includes an active material and a binder comprising a salt of a sulfonated polymer.

[0054] The inventors have found that the salts of sulfonated polymers have particular utility as binders in electrode active layers. In addition, when used as a binder, the increase in ESR of other equivalent devices using the salts of sulfonated polymers is significantly lower than that when using the standard binder CMC. Surprisingly, the inventors have also found that the salts of sulfonated polymers have comparable active material dispersibility in aqueous systems compared to CMC. Dispersibility is an important property of a binder because current methods typically involve applying a slurry containing a binder, a solvent, and an active material to a conductive surface. Thus, any non - uniformity and aggregation / coalescence of the particles in the slurry can be reflected in the deposited electrode active layer. In an electrode slurry of a mixture containing particles such as an active material and a conductive material, the depolymerization and even dispersion of the materials in the slurry can optimize the electrode / electrolyte contact and conductivity in the entire dried electrode active layer, thereby conferring performance advantages to the energy conversion / storage device. Without wishing to be bound by any particular theory, as measured by the rate of increase of ESR over time and capacitance loss, as well as improved frequency response, the excellent dispersibility of the binders described herein significantly improves the lifetime performance of supercapacitors using such binders compared to supercapacitors using CMC as a binder. In addition, the chemical composition of the binders herein advantageously avoids chemical side reactions during charge - discharge cycles, provides good adhesion to the current collector, and / or provides good cohesion between the binder and the active material.

[0055] In some embodiments, the salts of sulfonated polymers described herein are water - soluble, which enables environmentally friendly aqueous processing for the production of electrode active layers. ​​

[0056] Finally, when the salts of the sulfonated polymers described herein are used as binders, as compared to conventional CMC binders, they advantageously reduce gas accumulation during use. Gas accumulation can lead to premature device failure. Other advantages of the binders described herein will be apparent from the following description.

[0057] Although certain sulfonated polymers are known for their ionic properties and have thus far been found to be used in charge transfer or membrane applications, the inventors have for the first time discovered their use as binders, particularly in composite electrodes that can be used in energy conversion and storage devices. The salts of sulfonated polymers have unexpected properties in the form of excellent dispersion in aqueous electrode active material mixtures in this specific application, as well as beneficial effects in terms of reduced ESR and reduced gas production as compared to standard binders in the art, which have not been appreciated at all previously.

[0058] For the purposes of the following discussion, the term "supercapacitor" refers to devices that are also named as ultracapacitors, electrochemical double layer capacitors (EDLCs), electrochemical capacitors, pseudocapacitors, hybrid supercapacitors, etc. All such devices are considered to be within the scope of this disclosure. Additionally, although the invention described herein has been developed primarily for supercapacitors and will be described with reference to that application, it should be understood that the binders described herein can also be applicable to other energy storage devices such as batteries. In the present disclosure, all such devices are considered to be energy conversion or storage devices.

[0059] As used herein, the term "electrode active layer" refers to a layer that includes materials that are active in the storage and / or conversion of chemical energy and / or electrical energy. The electrode active layer includes at least one active material and a binder. A conductive surface that acts as a current collector forms part of the entire composite electrode, where the electrode active layer is one part.

[0060] As used herein, the term "substantially" means within + / - 5%, + / - 4%, + / - 3%, + / - 2% or + / - 1%.

[0061] Electrode active layer

[0062] Described herein is an electrode active layer for an energy conversion or storage device, which includes an active material and a binder containing a salt of a sulfonated polymer. The sulfonic acid group has the formula -SO3 - and has the following structure as a functional group, where R is an organic group:

[0063]

[0064] As used herein, the term "sulfonate" refers to the sulfonate anion functional group, which is the deprotonated form of a sulfonic acid. It should be understood that any reference to a sulfonic acid herein implicitly refers to a sulfonate salt (as opposed to a sulfonate ester), and these salts differ in that they include a non-hydrogen cation as the counterion to the negative charge carried by the sulfonate anion. Sulfonated polymers are those that contain sulfonate functional groups. To avoid doubt, sulfonic acid polymers in their acid form are not within the scope of the term sulfonate salts.

[0065] In one embodiment, the adhesives herein include non-perfluorinated sulfonic acid polymers, which refers to sulfonic acid polymers in which every hydrogen attached to carbon in the organic polymer has been replaced by fluorine. In such cases, it is understood that fluorination of some but not all of the organic carbon in the polymer is acceptable. In another embodiment, the adhesives herein can include non-fluorinated sulfonic acid polymers. "Non-fluorinated" means that the sulfonic acid polymer contains no fluorine atoms at all. In one embodiment, whether sulfonated or not, the adhesives herein do not contain perfluorinated polymers and perfluorinated monomers. In one embodiment, whether sulfonated or not, the adhesives herein do not contain fluorinated polymers and fluorinated monomers.

[0066] In some embodiments, the adhesives herein include non-chemically crosslinked sulfonic acid polymers. "Non-chemically crosslinked" means that the polymer does not contain chemical (i.e., covalent) crosslinks and does not use chemical (i.e., covalent) crosslinking agents.

[0067] It will be understood that cations (such as metal cations) can have a physical (e.g., ionic) crosslinking effect in negatively charged polymers. In polymers including the adhesives herein, such physical crosslinking is acceptable.

[0068] Sulfonated polymers can have any suitable structure. In one embodiment, the sulfonated polymer is derived from at least some monomers containing sulfonate groups. In other embodiments, the polymer is modified after synthesis to contain sulfonate groups, such as by reacting other functional groups in the polymer to form sulfonate groups. Those skilled in the art will be familiar with methods for producing various sulfonic acid polymers (such as Khomein et al. (2021), Sulfonatedaromaticpolymerasafuture proton exchange membrane: A review of sulfonation and crosslinking methods, (Sulfonated Aromatic Polymers as Future Proton Exchange Membranes: A Review of Sulfonation and Crosslinking Methods), Renewable and Sustainable Energy Reviews (137, the content of which is incorporated herein by cross-reference), or those skilled in the art can utilize commercially available sulfonic acid polymers such as poly(4-styrenesulfonic acid) solution, 2-propen-1-sulfonic acid (allylsulfonic acid), or 2-acrylamido-2-methyl-1-propanesulfonic acid, each of which can react with a base (such as a hydroxide or carbonate) to form its salt, or poly(sodium 4-benzenesulfonate), vinylsulfonic acid, sodium salt, or sodium 2-methyl-2-propene-1-sulfonate, all of which are available from Sigma-Aldrich).

[0069] In one embodiment, the sulfonated polymer is derived from monomers, each monomer including a sulfonic acid group. In one embodiment, the sulfonated polymer is derived from a monomer that includes a substituted C2 to C6 linear or branched alkene. The alkene preferably includes a single vinyl (C═C) group. In one embodiment, the substituted C2 to C6 linear or branched alkene is a C2 alkene (C═C), C3 alkene (C═C-C), C4 alkene (C═C-C-C), (C-C═C-C), (C═C(C)-C), etc., C5 alkene, or C6 alkene (hydrogen and substituents not shown). The substitution can occur on any carbon in the C2 to C6 linear or branched alkene.

[0070] Although the C2 to C6 linear or branched alkene can include any suitable substituent, in one embodiment, the substituent includes one or more of the following: -R1SO3 - , -R1ArSO3 - , -C(═O)NHR1SO3 - , -C(═O)NHR1ArSO3 - , -C(═O)NHArR1SO3 - , -ArR1SO3 - or -ArSO3 - ; where R1 = C1 to C6 linear or branched alkyl or bond, and Ar = aryl. In one embodiment, the aryl is phenyl.

[0071] In one embodiment, the monomer is H2C═CH-R1SO3 - 、H2C═CH-R1ArSO3 - 、H2C═CH-ArR1SO3 - or H2C═CH-ArSO3 -, where R1 = a C1 to C6 linear or branched alkyl or a bond, and Ar = an aryl group. In one embodiment, the monomer is (C3H5)-R1SO3 - , (C3H5)-R1ArSO3 - , (C3H5)-ArR1SO3 - or (C3H5)-ArSO3 - , where R1 = a C1 to C6 linear or branched alkyl or a bond, and Ar = an aryl group. In another embodiment, the monomer is H2C=CH-CH2-R1SO3 - , H2C=CH-CH2-R1ArSO3 - , H2C=CH-CH2-ArR1SO3 - or H2C=CH-CH2-ArSO3 - , where R1 = a C1 to C6 linear or branched alkyl or a bond, and Ar = an aryl group. In one embodiment, the monomer is (C4H7)-R1SO3 - , (C4H7)-R1ArSO3 - , (C4H7)-ArR1SO3 - or (C4H7)-ArSO3 - , where R1 = a C1 to C6 linear or branched alkyl or a bond, and Ar = an aryl group.

[0072] In another embodiment, the monomer is H2C=CH-CH2-R1SO3 - , H2C=CH-CH2-R1ArSO3 - , H2C=CH-CH2-ArR1SO3 - or H2C=CH-CH2-ArSO3 - , where R1 = a C1 to C4 linear or branched alkyl or a bond, and Ar = a phenyl group. In another embodiment, the monomer is H2C=CH-R1SO3 - , H2C=CH-R1ArSO3 - , H2C=CH-ArR1SO3 - or H2C=CH-ArSO3 - , where R1 = a C1 or C2 linear alkyl or a bond, and Ar = a phenyl group.

[0073] In a further embodiment, the monomer is -C(=O)NHR1SO3 - , -C(=O)NHR1ArSO3 - or -C(=O)NHArR1SO3 -, where R1 = C1 to C6 linear or branched alkyl or a bond, and Ar = phenyl. In a further embodiment, the monomer is -C(=O)NHR1SO3 - , where R1 = C 3-5 branched alkyl, and Ar = phenyl, or where, R1 = -C(CH3)2CH2-, and Ar = phenyl.

[0074] In one embodiment, the sulfonate group in the polymer is a benzenesulfonate group, as shown below:

[0075]

[0076] In one embodiment, the sulfonated polymer is derived from monomers, each monomer containing one benzenesulfonate group. In one embodiment, the sulfonated groups in the polymer include benzenesulfonate groups.

[0077] In one embodiment, the binder comprises a salt of poly(benzenesulfonic acid), poly(vinylsulfonic acid), poly(2-acrylamido-2-methyl-1-propanesulfonic acid), poly(2-propene-1-sulfonic acid) or poly(2-methyl-2-propene-1-sulfonic acid). In one embodiment, the binder consists of a salt of poly(benzenesulfonic acid), poly(vinylsulfonic acid), poly(2-acrylamido-2-methyl-1-propanesulfonic acid), poly(2-propene-1-sulfonic acid) or poly(2-methyl-2-propene-1-sulfonic acid). In one embodiment, the binder comprises a salt of poly(benzenesulfonic acid). In one embodiment, the binder comprises a salt of poly(2-acrylamido-2-methyl-1-propanesulfonic acid). In one embodiment, the binder comprises a salt of poly(2-propene-1-sulfonic acid). In one embodiment, the binder comprises a salt of poly(2-methyl-2-propene-1-sulfonic acid). In one embodiment, the binder does not comprise a salt of poly(vinylsulfonic acid).

[0078] The salts of the sulfonated polymers can include any suitable cation. In one embodiment, the polymer includes a Group I metal cation, a Group II metal cation, a transition metal cation, or an ammonium-based cation as a counterion. The salts of the sulfonated polymers can include one or more counterions selected from Group I or Group II metal cations. Such embodiments can be advantageous where water solubility for processing is highly desirable. Such cations include lithium cation, potassium cation, sodium cation, cesium cation, magnesium cation, and calcium cation. In one embodiment, the salts of the sulfonated polymers can include a Group I metal cation. In one embodiment, the salts of the sulfonated polymers can include a Group II metal cation. In some embodiments, the salts of the sulfonated polymers include sodium cation, lithium cation, magnesium cation, or calcium cation, such as sodium salts, lithium salts, magnesium salts, or calcium salts. In some embodiments, a mixture of different cations can be used as the counterions for the same polymer chain, such as a mixture of Li and Na, or a mixture of Ca and Mg cations. Other cation combinations will be apparent to those skilled in the art. In other embodiments, the salts of the sulfonated polymers can include one or more transition metal cations, such as zinc cation, iron cation, and / or nickel cation. In one embodiment, the binder consists of a single salt of the sulfonated polymer. In another embodiment, the binder includes a mixture of two or more different salts of the sulfonated polymers.

[0079] In some embodiments, the cation can be selected to coordinate with the ionic system of the energy storage and / or conversion device. The ionic homogeneity between the electrochemically active material and the binder in the device can prevent competitive redox reactions. By way of non-limiting example only, a hybrid Li-ion / supercapacitor device can include a lithium salt of the sulfonated polymer, and a hybrid K-ion / supercapacitor device can include a potassium salt of the sulfonated polymer. Other energy storage and conversion devices that utilize sodium, zinc, iron, or nickel, etc. can utilize sodium salts, zinc salts, iron salts, or nickel salts, etc. of the sulfonated polymer.

[0080] In one embodiment, the salts of the sulfonated polymers can include ammonium-based cations. Such cations are commonly used as the cationic component in EDLCs and include, but are not limited to, primary, secondary, tertiary, or quaternary alkylammonium cations and their substituted equivalents, such as 2-(methylthio)ethylammonium cation. Quaternary ammonium cations are known to be particularly stable at the typical operating voltages of supercapacitors. Quaternary ammonium cations are the most commonly used cations in EDLC electrolytes and are suitable for use as the cations of the salts in the binders described herein. Suitable quaternary ammonium cations include, but are not limited to, tetramethylammonium cation, methyltriethylammonium cation, tetraethylammonium cation, tetrapropylammonium cation, or tetrabutylammonium cation. In one embodiment, the quaternary ammonium cation has the following chemical structure:

[0081]

[0082] wherein, R 1 , R 2 , R 3 and R 4 are each an alkyl substituent. In one embodiment, R 1 , R 2 , R 3 and R 4 are each independently a C1-C7 straight-chain or branched-chain alkyl chain. In one embodiment, R 1 , R 2 , R 3 and R 4 are independently a C1-C4 straight-chain or branched-chain alkyl chain. In one embodiment, R 1 , R 2 , R 3 and R 4 are independently a C1-C2 straight-chain alkyl chain. In one embodiment, R 1 is different from at least one of R 2 , R 3 and R 4 . In one embodiment, R 1 , R 2 , R 3 and R 4 are different from each other.

[0083] In another embodiment, the salt of the sulfonated polymer may include a nitrogen-containing heterocyclic cation. Suitable examples are spiro-bis-pyrrolidinium (SBP), N,N-dimethylpyrrolidinium, N-methyl-N'-propylpyrrolidinium, N,N'-dimethylimidazolium, N-methyl-N'-ethylimidazolium, and N-methyl-N'-propylimidazolium. In one embodiment, the quaternary ammonium cation is a nitrogen-containing heterocyclic cation having the following chemical structure:

[0084]

[0085] wherein, R 5 and R 6 are each an alkyl substituent. In one embodiment, R 5 and R 6 each independently comprise a C1-C7 straight-chain or branched-chain alkyl chain. In one embodiment, R 5 is different from R 6 .

[0086] The sulfonated polymers described herein can have any suitable average molecular weight, which refers to the average molecular weight of each polymer chain. In one embodiment, the average molecular weight of the polymer is from about 20,000 g / mol to about 2,000,000 g / mol, or from 20,000 g / mol to 100,000 g / mol, or from 70,000 g / mol to 125,000 g / mol, or from 85,000 g / mol to 140,000 g / mol, or from 100,000 g / mol to 500,000 g / mol, or from 250,000 g / mol to 750,000 g / mol, or from 500,000 g / mol to 1,000,000 g / mol, or from 1,000,000 g / mol to 1,500,000 g / mol, or from 1,250,000 g / mol to 2,000,000 g / mol, or from 70,000 g / mol to 1,250,000 g / mol, or 50,000 g / mol, 60,000 g / mol, 70,000 g / mol, 75,000 g / mol, 80,000 g / mol, 90,000 g / mol, 100,000 g / mol, 110,000 g / mol, 120,000 g / mol, 130,000 g / mol, 140,000 g / mol, 150,000 g / mol, 250,000 g / mol, 500,000 g / mol, 1,000,000 g / mol, 1,250,000 g / mol, 1,500,000 g / mol, 1,750,000 g / mol or 2,000,000 g / mol. The molecular weight can be the molecular weight of the polymer in its protonated form before it is converted to a salt.Alternatively, in other embodiments, the average molecular weight of the polymeric salt is from about 50,000 g / mol to about 2,000,000 g / mol, or from 50,000 g / mol to 10,000 g / mol, or from 70,000 g / mol to 125,000 g / mol, or from 85,000 g / mol to 140,000 g / mol, or from 100,000 g / mol to 500,000 g / mol, or from 250,000 g / mol to 750,000 g / mol, or from 500,000 g / mol to 1,000,000 g / mol, or from 1,000,000 g / mol to 1,500,000 g / mol, or from 1,250,000 g / mol to 2,000,000 g / mol, or from 70,000 g / mol to 1,250,000 g / mol, or 50,000 g / mol, 60,000 g / mol, 70,000 g / mol, 75,000 g / mol, 80,000 g / mol, 90,000 g / mol, 100,000 g / mol, 110,000 g / mol, 120,000 g / mol, 130,000 g / mol, 140,000 g / mol, 150,000 g / mol, 250,000 g / mol, 500,000 g / mol, 1,000,000 g / mol, 1,250,000 g / mol, 1,500,000 g / mol, 1,750,000 g / mol or 2,000,000 g / mol. In such embodiments, once the polymer has been converted to a salt, the molecular weight includes the counterion of the salt. In one embodiment, the molecular weight of the polymer is from about 70,000 g / mol to about 100,000 g / mol. In one embodiment, the molecular weight of the polymeric salt is from about 70,000 g / mol to about 100,000 g / mol. In one embodiment, the molecular weight of the polymeric salt is from about 100,000 g / mol to about 1,000,000 g / mol. In one embodiment, the molecular weight of the polymeric salt is from about 70,000 g / mol to about 900,000 g / mol.

[0087] The binder may include any suitable wt% of the salt of the sulfonated polymer. In some embodiments, the binder is a pure salt of the sulfonated polymer such that the binder comprises about 100 wt%, or at least 99%, 98%, 95% or 90% of the salt of the sulfonated polymer.

[0088] In another embodiment, the binder includes a copolymer derived from two or more different sulfonated monomers or one or more sulfonated monomers and at least one other monomer. The nature of the copolymer is not particularly limited, but a random copolymer may be preferred over a block copolymer.

[0089] In the case where the copolymer comprises two or more different sulfonated monomers, each monomer may be as described above. Alternatively, other sulfonated monomers may be used, such as 2-acrylamido-2-methyl-1-propanesulfonate (PAMP).

[0090] In the case where the copolymer comprises at least one other monomer, the at least one other monomer may be sulfonated or may be non-sulfonated. The at least one other monomer may be non-fluorinated. The at least one other monomer may be non-perfluorinated. In one embodiment, the at least one other monomer comprises an optionally substituted C2 to C6 cyclic, linear or branched olefin, such as a C2 olefin (C═C), a C3 olefin (C═C-C), a C4 olefin (C═C-C-C), (C-C═C-C), (C═C(C)-C), etc., a C5 olefin or a C6 olefin (hydrogen and substituents not shown). Optional substituents may be phenyl, a C1 to C6 linear or branched alkyl group, a carboxylic acid, a carbonyl or an amide. In one embodiment, the at least one other monomer is a substituted olefin (such as 1,2-difluoroethylene, or tetrafluoroethylene, or maleic acid or its salt). In one embodiment, the at least one other monomer is styrene and butadiene. In one embodiment, the at least one other monomer is an acrylic monomer (such as acrylic acid or its salt, methacrylic acid or its salt, or butylacrylic acid or its salt). In one embodiment, the C2 to C6 linear or branched olefin is unsubstituted. In one embodiment, the at least one other monomer is a cyclic anhydride having a C═C bond (such as maleic anhydride). In one embodiment, each sulfonated monomer comprises one sulfonic acid group, optionally each sulfonated monomer comprises one benzenesulfonic acid group, and the at least one other monomer does not contain a sulfonic acid group.

[0091] In one embodiment, when the binder comprises a copolymer derived from two or more different sulfonated monomers or one or more sulfonated monomers and at least one other monomer, the copolymer comprises at least 30 wt%, at least 40 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt% or at least 99 wt% of sulfonated monomers, or comprises 30 wt% to 99 wt%, or 30 wt% to 50 wt%, or 50 wt% to 75 wt%, or 70 wt% to 90 wt%, or 60 wt% to 99 wt% of sulfonated monomers, or comprises 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, 95 wt% or 99 wt% of sulfonated monomers, at least 30 mol%, at least 40 mol%, at least 50 mol%, at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol%, at least 95 mol% or at least 99 mol% of sulfonated monomers, or comprises 30 mol% to 99 mol%, or 30 mol% to 50 mol%, or 50 mol% to 75 mol%, or 70 mol% to 90 mol%, or 60 mol% to 99 mol% of sulfonated monomers, or comprises 30 mol%, 40 mol%, 50 mol%, 60 mol%, 70 mol%, 80 mol%, 90 mol%, 95 mol% or 99 mol% of sulfonated monomers.

[0092] In one embodiment, the binder comprises a mixture of a salt of a sulfonated polymer and at least one other polymer (such as a polymer produced from at least one of the aforementioned other monomers). In one embodiment, the at least one other polymer can be PVDF, PTFE, SBR or an acrylic-based polymer. In such embodiments, the mixture can comprise at least 30 wt%, at least 40 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or at least 99 wt% of the sulfonated polymer or its salt, or comprises 30 wt% to 99 wt%, or 30 wt% to 50 wt%, or 50 wt% to 75 wt%, or 70 wt% to 90 wt%, or 60 wt% to 99 wt% of the sulfonated polymer or its salt. In one embodiment, the binders herein comprise a salt of a sulfonated polymer mixed or blended with a conventional compound used as a binder in an energy storage device. Conventional compounds suitable for mixing or using in a blend with a salt of a sulfonated polymer as described herein include, but are not limited to, PVDF, PTFE, SBR or acrylic-based binders.

[0093] In one embodiment, the adhesives herein are completely soluble in water or have a solubility of at least 0.02 g / mL in water. In one embodiment, the sulfonated polymers comprising the adhesives herein are completely soluble in water or have a solubility of at least 0.1 g / mL in water.

[0094] In one embodiment, the adhesives herein have a pH of about 7, or from 6 to 8 (such as from 6.5 to 7.5, or from 6.8 to 7.2), or about 6, 6.25, 6.5, 6.75, 7.0, 7.25, 7.5, 7.75 or 8. In some embodiments, the pH of the adhesive can be adjusted using a base (such as a metal hydroxide) or an acid (such as tetrafluoroboric acid, TFSI acid or methanesulfonic acid).

[0095] The electrode active layer for an energy conversion or storage device described herein comprises an active material. The electrode "active material" can include, but is not limited to, cathode materials, anode materials, and electrochemically active materials, which can include solvents, additives, and / or electrolyte salts depending on the application.

[0096] The active material in the electrode active layer described herein is not particularly limited. In one embodiment, the active material is carbon-based. In one embodiment, the active material is amorphous carbon, carbon nanotubes, graphene, graphene oxide, reduced graphene oxide, or activated carbon.

[0097] Activated carbon has a high surface area and porosity, which makes it particularly suitable for use in EDLC supercapacitor devices, where their high surface area and porous nature increase the effective area of the capacitor plates and thus increase the maximum achievable capacitance. Thus, in one embodiment, the active material is activated carbon. In one embodiment, the activated carbon has a surface area of at least 1200 m 2 / g. In another embodiment, the carbon-based material has a surface area of at least 400 m 2 / g. In an embodiment, the activated carbon comprises having a surface area between 1200 m 2 / g and 3000 m 2activated carbon with a surface area between [value] and [value] m² / g. In another embodiment, the activated carbon has a particle size D50 between 3 μm and 10 μm, D10 > 1 μm, and D90 < 30 μm. In another embodiment, the activated carbon is microporous carbon, where the size of more than 50% of the pore volume is less than 2 nm. Examples of commercially available microporous activated carbons suitable for use as the active material herein are MSP20 (Kansai Coke), MSC-30 (Kansai Coke), FAR01X (Kansai Coke), YP-80F (Kuraray), RP-25 (Kuraray), RP-20 (Kuraray), NY1151 (Kuraray Chemical Co., Ltd.), NK261H (Kuraray), HDLC 20B STUW (Haycarb PLC), DLC 30 (Haycarb PLC), DLC 20P (Haycarb PLC), HCE-201 (Haycarb PLC), HCE-202 (Haycarb PLC), ACS20 (China Steel Chemical Corporation), ACS 25 (China Steel Chemical Corporation), Yec-200E (IHUAN Carbon), YEC-8A (IHUAN Carbon), YEC-8B (IHUAN Carbon), Y-Carbon (Y-Carbon Co.), ZL-302 (Huzhou Sensheng Activated Carbon Co., Ltd.), MCSP 2005 (Calgon Mitsubishi Chemical Corporation), MCSP 1805A (Calgon Mitsubishi Chemical Corporation), and MCSP 1805-1 (Calgon Mitsubishi Chemical Corporation).

[0098] In another embodiment, the activated carbon can be classified as mesoporous carbon, where more than 50% of the pore volume has a pore diameter greater than 2 nm. Examples of commercially available mesoporous carbons suitable for use as the active material herein are P2-15 (EnerG2), MSA-20 (Kansai Coke and Chemicals), YP-50F (Kuraray), NY1251H (Kuraray), YPS (Kuraray), ACS15 (China Steel Chemical Corporation), TDA 60 (TDA Research Institute), SO-15A (TDA Research Institute), and ACC (Xiamen All Carbon Co.).

[0099] In other embodiments, the active material can be oxide-based, such as transition metal oxides. These oxide materials are often used as cathode active materials in batteries or supercapacitors and are sometimes used as anodes. Examples of transition metal oxides can include NiO, ZnO, RuO2, MnO2, Co3O4, WO3, V2O5, LiTiO4, and mixed metal oxides (such as XCo2O4 (X = Mn, Cu, Ni) and AMoO4 (A = Co, Mn, Ni, Zn)). Other cathode materials typically used in batteries, hybrid capacitors, or pseudocapacitors include layered oxides, oxyanions, polyanions, and Prussian blue and its analogs, LiCoO2, LiMn2O4, LiFePO4, lithium nickel manganese cobalt oxide (Lithium Nickel Manganese Cobalt, NCM), commonly denoted as LiNiMnCoO2, lithium nickel cobalt aluminium oxides (Lithium nickel cobalt aluminium oxides, NCA), commonly denoted as LiNiCoAlO2, lithium nickel cobalt manganese aluminium oxide (Lithium nickel cobalt manganese aluminium oxide, NCMA) LiNiCoMnAlO2, LiNiO2, NaFeMnO2, NaMnMgO2, NaNiMnMgO2, KMnO2, KCoO2, etc.

[0100] In one embodiment, a carbon-based anode battery-type material can be used as the active material. In another embodiment, the active material is graphite, hard carbon, or soft carbon. In one embodiment, the anode can be silicon-based.

[0101] In certain embodiments, the active material is a composite of a carbon-based and an oxide-based system, such as graphene oxide or activated carbon / metal oxide composites. Suitable commercial sources of active materials (such as activated carbon) are known to those skilled in the art.

[0102] The electrode active layer herein can have any suitable thickness. In one embodiment, the electrode active layer has a thickness of 5 μm to 200 μm, or 5 μm to 100 μm, 5 μm to 80 μm, 5 μm to 60 μm, 5 μm to 50 μm once dried.

[0103] The binder can be present in the electrode active layer in any suitable amount. In the absence of an electrolyte, the amount of the binder in the electrode active layer can be calculated as the weight percentage of all solid components in the electrode active layer. In one embodiment, the binder is present in an amount of 1 wt% to 30 wt% of the electrode active layer, or in an amount of 1 wt% to 10 wt%, or 5 wt% to 20 wt%, or 10 wt% to 25 wt%, or 15 wt% to 30 wt%, or 2 wt% to 20 wt%, or 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 12.5 wt%, 15 wt%, 17.5 wt%, 20 wt%, 25 wt% or 30 wt% of the electrode active layer. wt% can be calculated as [mass 粘合剂 / (mass 粘合剂 + mass 活性材料 + mass 其他固体，如果存在的话 )] × 100.

[0104] In one embodiment, the electrode active layer further includes a conductive material. When the conductivity of the active material in the energy storage / conversion device is insufficient, or when an increase in conductivity within the electrode active layer is desired, a conductive material is typically required. In some embodiments, the use of a carbon-based active material such as activated carbon may require the addition of a conductive material.

[0105] The nature of the conductive material is not particularly limited. In some embodiments, the conductive material is conductive carbon, such as carbon black, graphite, graphene, carbon nanotubes, etc. In one embodiment, the conductive material is conductive carbon or carbon black. In one embodiment, the carbon black has a BET (N2) surface area of about 100 m 2 / g to 500 m 2 / g. In another embodiment, the carbon black has a submicron primary particle size between 10 nm and 100 nm. Carbon black particles typically aggregate and require high shear to disperse them adequately in the electrode slurry. Suitable commercial sources of the conductive material (such as conductive carbon) are known to those of ordinary skill in the art and include Printex carbon black, such as L6 (Orion Carbons), kappa 100 (Orion Engineered Carbons), XE2 (Orion Engineered Carbons), ENSACO 150G (IMERYS), ENSACO 210G (IMERYS), ENSACO 250G (IMERYS), ENSACO 250F (IMERYS), ENSACO 260G (IMERYS), ENSACO 350G (IMERYS), Super C65 (IMERYS), HP (Cabot), LITX300 (Cabot), LITX200 (Cabot), VXC72R (Cabot), BP 700 (Cabot), BP 2000 (Cabot), SC2A (Cabot), TPX1278 (Cabot), Lump Black (Degussa), Ketjenblack EC300J (Akzo Noble), Ketjenblack EC600JD (Akzo Noble), E-MM-198G (Timcal), Super P (Timcal).

[0106] Composite Electrode

[0107] This document describes a composite electrode that includes an electrode active layer on a conductive surface, wherein the electrode active layer includes an active material and a binder containing a salt of a sulfonated polymer.

[0108] This document also describes the use of a salt of a sulfonated polymer described herein as a binder in the electrode active layer of a composite electrode.

[0109] The electrode active layer in the composite electrode is in contact with a current collector, which is typically fabricated in situ to maximize the adhesion of the electrode active layer to the current collector. In such embodiments, the binder and the active material are processed into an electrode paste in a solvent, and the electrode paste is applied to the current collector using any suitable application device. The solvent is then removed by a drying process, leaving an electrode active layer including the binder and the active material on the current collector.

[0110] Suitable methods for producing the composite electrode are described elsewhere herein. Although the current collector is not particularly limited and can generally include any conductive material, in some embodiments, the current collector is a metal foil. Suitable metal foils can include aluminum foil or copper foil, but other metal foils may also be suitable.

[0111] equipment

[0112] The present invention also describes an energy storage device including the composite electrode described above. Although the energy storage device is not particularly limited, in one embodiment, the energy storage device is a supercapacitor or a battery. In one embodiment, the energy storage device is a supercapacitor. The supercapacitor may be a prismatic supercapacitor or a cylindrical supercapacitor. In one embodiment, the energy storage device is a battery. In one embodiment, the battery is a Li-ion battery, a Na-ion battery, a K-ion battery, an Al-ion battery, or a Ca-ion battery. In one embodiment, the energy storage device is a supercapacitor-battery hybrid. In one embodiment, the hybrid device is a Li-ion / supercapacitor hybrid, a K-ion / supercapacitor hybrid, or a Na-ion / supercapacitor hybrid, or an Al-ion / supercapacitor hybrid, or a Ca-ion / supercapacitor hybrid.

[0113] The adhesives of the present invention can be used to produce symmetric or asymmetric energy storage devices. In a symmetric device, the same adhesive is used for each electrode. In an asymmetric device, the adhesive composition is changed such that the first and second electrodes have different adhesives. Asymmetric electrodes allow for higher voltages and higher energy densities in supercapacitors. By varying the energy density on each electrode to ensure that the voltage drop across the electrode interface is optimal for energy harvesting and stability of the electrode, higher voltage operation can be achieved. Batteries are inherently asymmetric devices since the chemical composition of each electrode is optimized for oxidation or reduction. In this case, the adhesive is selected to be stable in the electrochemical environment at each electrode.

[0114] Thus, in one embodiment, the energy storage device includes at least two composite electrodes, and each composite electrode includes the same adhesive. This embodiment is particularly suitable for supercapacitors.

[0115] In another embodiment, the energy storage device includes two composite electrodes, wherein each composite electrode includes a different adhesive. This embodiment is applicable to supercapacitors, batteries, and hybrid devices.

[0116] In the energy storage and conversion devices herein, the space between the electrodes typically contains an electrolyte, which is generally a solvent including dissolved salts. In a supercapacitor, the electrolyte is the ion source required to form a double layer on the surface of the carbon-containing electrode active layer, but also allows for ion conduction between the opposing electrodes. The electrolyte in the devices herein is not particularly limited. Those skilled in the art will be familiar with electrolytes suitable for use in energy storage and conversion devices and will be familiar with electrolytes suitable for use in the devices described herein. In one embodiment, the electrolyte includes an ionic liquid or an organic sulfur compound (such as sulfolane), an organic carbonate (such as propylene carbonate or γ-butyrolactone), and at least one organic salt (such as an organic tetrafluoroborate).

[0117] In some energy conversion and storage devices, a separator may be required to physically isolate the electrodes and prevent electrical short circuits. In supercapacitors, the separator is typically a porous material (such as a porous polymer) that allows the storage of electrolyte during charge and discharge and transfers ions from the anode to the cathode. The separator in this article is not particularly limited, and those skilled in the art will be familiar with suitable separators for the devices in this article. In one embodiment, the separator is made of a polymer (such as high-density polyethylene, polypropylene, PTFE, PET, or PTFE). In another embodiment, the separator is made of fibers (such as cellulose fibers, glass fibers, or aramid fibers).

[0118] Method for producing slurry and electrode

[0119] This article describes an electrode paste for producing an electrode active layer, the electrode paste comprising: an active material; a binder comprising a salt of a sulfonated polymer; and a solvent.

[0120] The electrode paste may include any suitable amount of solvent, such as an amount of solvent sufficient to disperse the active material and achieve a spreadable viscosity of the electrode paste on a conductive surface. In one embodiment, the electrode paste includes from about 60 wt% to about 95 wt% of solvent, or includes from 60 wt% to 80 wt%, or 75 wt% to 90 wt%, or 80 wt% to 95 wt% of solvent, or includes 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, or 95 wt% of solvent. The solvent is not particularly limited in this article, but for environmental reasons, water is the preferred solvent. In one embodiment, the solvent is an organic solvent, such as methanol, ethanol, or X. In another embodiment, the solvent is water. In another embodiment, the solvent is a mixture of methanol or ethanol in water. Other suitable solvents will be apparent to those skilled in the art.

[0121] The electrode paste in this article may include any suitable weight percentage of binder based on solids. In one embodiment, the electrode paste in this article includes from 1 wt% to 30 wt% of binder based on solids, or includes from 1 wt% to 10 wt% based on solids, or 5 wt% to 20 wt%, or 10 wt% to 25 wt%, or 15 wt% to 30 wt%, or 2 wt% to 20 wt%, or 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 12.5 wt%, 15 wt%, 17.5 wt%, 20 wt%, 25 wt%, or 30 wt% of binder.

[0122] The active material of the slurry can be the same as the active material of the electrode active layer described elsewhere herein.

[0123] The electrode slurry herein can include any suitable weight percentage of active material based on solids. In one embodiment, the electrode slurry herein includes 50 wt% to 99 wt%, or 50 wt% to 75 wt%, or 70 wt% to 90 wt%, or 80 wt% to 99 wt%, or 55 wt% to 85 wt%, or 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 95 wt% or 99 wt% of active material based on solids.

[0124] In one embodiment, the electrode slurry can be a substantially uniform dispersion of the active material. In one embodiment, the electrode slurry includes a substantially uniform dispersion of active material particles. In one embodiment, the electrode slurry includes a substantially uniform dispersion of active material particles and conductive particles. In one embodiment, the electrode slurry is substantially free of agglomerates and aggregates of active material particles and / or conductive material particles. In one embodiment, the active material has a particle size distribution of D10 > 1 μm to D90 < 20 μm and 3 μm < D50 < 10 μm, or has a particle size distribution of D10 > 1 μm to D90 < 50 μm and 5 μm < D50 < 20 μm.

[0125] The electrode slurry can include any suitable weight percentage of conductive material based on solids. In one embodiment, the electrode slurry includes 5 wt% to 25 wt% of conductive material based on solids, or includes 5 wt% to 10 wt%, or 7 wt% to 15 wt%, or 10 wt% to 20 wt%, or 15 wt% to 25 wt%, or 10 to 25 wt%, or 5 wt%, 10 wt%, 15 wt%, 20 wt% or 25 wt% of conductive material based on solids.

[0126] Any suitable technique in the art can be used to synthesize the electrode slurry. In one embodiment, the binder is first dispersed in a solvent (such as water), and then the active material is added and the resulting mixture is blended. The blending conditions can include using a magnetic stir bar or other mechanical mixing device, and the mixing can continue for any suitable time period, such as a time period of 1 min to 48 h, or 1 h to 24 h, or 5 min to 1 h, or 1 h to 36 h. In some embodiments, if a conductive material is used, the conductive material can be added after mixing / blending the active material, and the mixture is blended for an additional time period of 1 min to 48 h, or 1 h to 24 h, or 5 min to 1 h, or 1 h to 36 h.

[0127] In one embodiment, the mixture is dispersed using a high-shear mixer for a period of 2 seconds to 30 seconds, or 30 seconds to 5 minutes, or 2 minutes to 10 minutes, or 2 seconds to 30 minutes. The high-shear dispersion can be appropriately carried out after an initial mixing or blending step.

[0128] In other embodiments, the active material and the conductive material are simultaneously dispersed in a binder / solvent mixture (such as water), and a single mixing step and an optional subsequent high-shear dispersion step are carried out.

[0129] Also described herein is a method of manufacturing an electrode active layer, including applying the electrode paste described herein to a current collector; and drying the electrode paste to remove the solvent.

[0130] The current collector is not particularly limited and generally can include any conductive material. In some embodiments, the current collector is a metal foil. Suitable metal foils can include aluminum foil or copper foil, but other metal foils may also be suitable. The current collector can have any suitable thickness. In some embodiments, the current collector is a metal foil having a thickness of 1 μm to 100 μm.

[0131] The applying step can include any suitable techniques known in the art. In one embodiment, the applying step includes using screen printing, gravure printing, inkjet printing, slot die printing, K-bar coating, etc. to apply the electrode paste on the current collector. In one embodiment, the electrode paste is applied on the current collector in the form of a thin layer (such as a layer with a thickness of 1 μm to 100 μm or 10 μm to 1000 μm). In one embodiment, the layer is applied on the current collector with substantially the same thickness.

[0132] The drying step can include any suitable techniques known in the art. In one embodiment, the electrode paste on the current collector is dried in a vacuum oven, such as continuously dried for a period of 5 min to 24 h at a temperature of 80°C to 160°C and a reduced pressure of less than 200 mbar. During drying, the solvent evaporates to leave the binder and the active material (including any conductive material) on the current collector. In some embodiments, about 100% of the solvent is removed during the drying step, or at least 90%, 95%, or 99% of the solvent is removed during the drying step.

[0133] Embodiments

[0134] The following embodiments are disclosed herein:

[0135] Embodiment 1. An electrode active layer for an energy conversion or storage device, comprising:

[0136] An active material; and

[0137] A binder comprising a salt of a sulfonated polymer.

[0138] Embodiment 2. The electrode active layer according to Embodiment 1, wherein the sulfonated polymer comprises substituted C2 to C6 linear or branched olefin monomers.

[0139] Embodiment 3. The electrode active layer according to Embodiment 1 or Embodiment 2, wherein the sulfonated polymer comprises substituted C2 to C6 linear or branched olefin monomers, and the substituted C2 to C6 linear or branched olefin comprises one or more of the following as substituents: -R1SO3 - , -R1ArSO3 - , -ArR1SO3 - , -ArSO3 - or -C(=O)NHR1SO3 - , -C(=O)NHR1ArSO3 - , -C(=O)NHArR1SO3 - ;

[0140] wherein R1 = C1 to C6 linear or branched alkyl or a bond; and

[0141] Ar = aryl.

[0142] Embodiment 4. The electrode active layer according to Embodiment 3, wherein Ar = phenyl.

[0143] Embodiment 5. The electrode active layer according to any one of the foregoing embodiments, wherein the sulfonated polymer comprises a benzenesulfonic acid group.

[0144] Embodiment 6. The electrode active layer according to any one of the foregoing embodiments, wherein the sulfonated polymer comprises monomers, each monomer comprising one sulfonic acid group, optionally each monomer comprising one benzenesulfonic acid group.

[0145] Embodiment 7. The electrode active layer according to any one of the foregoing embodiments, wherein the sulfonated polymer comprises monomers selected from the following: styrenesulfonic acid, vinylsulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, 2-propene-1-sulfonic acid or 2-methyl-2-propene-1-sulfonic acid.

[0146] Embodiment 8. The electrode active layer according to Embodiment 7, wherein the sulfonated polymer comprises styrenesulfonic acid monomers.

[0147] Embodiment 9. The electrode active layer according to any one of the foregoing embodiments, wherein the salt of the sulfonated polymer comprises one or more counterions selected from the following: Group I metal cations, Group II metal cations, transition metal cations, quaternary ammonium cations or nitrogen-containing heterocyclic cations.

[0148] Embodiment 10. An electrode active layer according to any one of the foregoing embodiments, wherein the salt of the sulfonated polymer comprises one or more counterions selected from the group consisting of: lithium cation, potassium cation, sodium cation, cesium cation, magnesium cation, and calcium cation.

[0149] Embodiment 11. An electrode active layer according to any one of the foregoing embodiments, wherein the salt of the sulfonated polymer comprises sodium cation, potassium cation, lithium cation, magnesium cation, and / or calcium cation.

[0150] Embodiment 12. An electrode active layer according to any one of Embodiments 1 to 9, wherein the salt of the sulfonated polymer comprises one or more counterions selected from the group consisting of: optionally substituted alkylammonium cations such as tetramethylammonium, tetraethylammonium, tetrapropylammonium, or tetrabutylammonium, or 2-(methylthio)ethylammonium cation; or nitrogen-containing heterocyclic cations such as spiro-bis-pyrrolidinium (SBP), N,N-dimethylpyrrolidinium, N-methyl-N'-propylpyrrolidinium, N,N'-dimethylimidazolium, N-methyl-N'-ethylimidazolium, or N-methyl-N'-propylimidazolium.

[0151] Embodiment 13. An electrode active layer according to any one of the foregoing embodiments, wherein the sulfonated polymer has an average molecular weight of from about 50,000 g / mol to about 2,000,000 g / mol.

[0152] Embodiment 14. An electrode active layer according to Embodiment 13, wherein the sulfonated polymer has an average molecular weight of from about 70,000 g / mol to about 1,000,000 g / mol.

[0153] Embodiment 15. An electrode active layer according to any one of the foregoing embodiments, wherein the binder comprises at least 30% by weight of the salt of the sulfonated polymer.

[0154] Embodiment 16. An electrode active layer according to Embodiment 15, wherein the binder comprises at least 50% by weight of the salt of the sulfonated polymer.

[0155] Embodiment 17. An electrode active layer according to Embodiment 15 or 16, wherein the binder comprises at least 90% by weight of the salt of the sulfonated polymer.

[0156] Embodiment 18. An electrode active layer according to any one of the foregoing embodiments, wherein the sulfonic acid polymer is a copolymer comprising two or more different sulfonated monomers.

[0157] Embodiment 19. An electrode active layer according to any one of the foregoing embodiments, wherein the sulfonic acid polymer is a copolymer comprising one or more sulfonated monomers and at least one other monomer.

[0158] Among them, each sulfonated monomer includes a sulfonic acid group, and

[0159] among them, at least one other monomer has no sulfonic acid group.

[0160] Embodiment 20. The electrode active layer according to Embodiment 19, wherein each sulfonated monomer includes a benzenesulfonic acid group.

[0161] Embodiment 21. The electrode active layer according to Embodiment 19 or 20, wherein at least one other monomer is selected from one or more of the following: 1,2-difluoroethylene, tetrafluoroethylene, styrene, butadiene, maleic anhydride, maleic acid or its salts, acrylic acid or its salts, methacrylic acid or its salts, or butylacrylic acid or its salts.

[0162] Embodiment 22. The electrode active layer according to any one of the foregoing embodiments, wherein the sulfonated polymer is a sulfonated non-perfluorinated polymer.

[0163] Embodiment 23. The electrode active layer according to any one of the foregoing embodiments, wherein the sulfonated polymer is a sulfonated non-fluorinated polymer.

[0164] Embodiment 24. The electrode active layer according to any one of the foregoing embodiments, wherein the sulfonated polymer is not chemically crosslinked.

[0165] Embodiment 25. The electrode active layer according to any one of the foregoing embodiments, wherein the binder includes a mixture of salts of two or more different sulfonated polymers, or a mixture of a salt of a sulfonated polymer and at least one other polymer.

[0166] Embodiment 26. The electrode active layer according to Embodiment 25, wherein the other polymer is selected from PVDF, PTFE, SBR, or an acrylic-based polymer.

[0167] Embodiment 27. The electrode active layer according to any one of the foregoing embodiments, wherein the active material is amorphous carbon.

[0168] Embodiment 28. The electrode active layer according to Embodiment 27, wherein the active material is activated carbon.

[0169] Embodiment 29. The electrode active layer according to any one of the foregoing embodiments, further comprising a conductive material.

[0170] Embodiment 30. The electrode active layer according to Embodiment 29, wherein the conductive material is conductive carbon.

[0171] Embodiment 31. The electrode active layer according to any one of the foregoing embodiments, has a thickness of 1 μm to 20 μm.

[0172] Embodiment 32. An electrode active layer according to any one of the foregoing embodiments, wherein the binder is present in an amount of 1 wt% to 30 wt% of the electrode active layer.

[0173] Embodiment 33. An electrode active layer according to Embodiment 32, wherein the binder is present in an amount of 2 wt% to 20 wt% of the electrode active layer.

[0174] Embodiment 34. A composite electrode, comprising:

[0175] An electrode active layer according to any one of Embodiments 1 to 33 on a conductive surface.

[0176] Embodiment 35. An energy storage device, comprising the composite electrode according to Embodiment 34.

[0177] Embodiment 36. The energy storage device according to Embodiment 34, wherein the energy storage device is a supercapacitor.

[0178] Embodiment 37. The energy storage device according to Embodiment 34, wherein the energy storage device is a battery.

[0179] Embodiment 38. The energy storage device according to any one of Embodiments 35 to 37, comprising two composite electrodes, wherein each composite electrode comprises a different binder.

[0180] Embodiment 39. The energy storage device according to Embodiment 38, wherein the different binders comprise different sulfonated polymers.

[0181] Embodiment 40. Use of a salt of a sulfonated polymer as a binder in an electrode active layer of a composite electrode.

[0182] Embodiment 41. An electrode paste for producing an electrode active layer, the electrode paste comprising:

[0183] An active material;

[0184] A binder comprising a salt of a sulfonated polymer; and

[0185] A solvent.

[0186] Embodiment 42. The electrode paste according to Embodiment 41, comprising 50 wt% to 95 wt% of a solvent.

[0187] Embodiment 43. The electrode paste according to Embodiment 41 or 42, wherein the solvent is water.

[0188] Embodiment 44. The electrode paste according to any one of Embodiments 41 to 43, the electrode paste comprising 1 wt% to 30 wt% of a binder based on solids.

[0189] Embodiment 45. The electrode paste according to Embodiment 41, wherein the electrode paste includes 2 wt% to 20 wt% of a binder based on solids.

[0190] Embodiment 46. The electrode paste according to any one of Embodiments 41 to 45, wherein the active material is amorphous carbon.

[0191] Embodiment 47. The electrode paste according to Embodiment 46, wherein the active material is activated carbon.

[0192] Embodiment 48. The electrode paste according to any one of Embodiments 41 to 47, wherein the electrode paste includes 50 wt% to 99 wt% of an active material based on solids.

[0193] Embodiment 49. The electrode paste according to any one of Embodiments 41 to 47, wherein the paste is a substantially homogeneous dispersion of the active material.

[0194] Embodiment 50. The electrode paste according to any one of Embodiments 41 to 49, further including a conductive material.

[0195] Embodiment 51. The electrode paste according to Embodiment 50, wherein the conductive material is conductive carbon.

[0196] Embodiment 52. The electrode paste according to Embodiment 50 or 51, wherein the electrode paste includes 5 wt% to 25 wt% of the conductive material based on solids.

[0197] Embodiment 53. The electrode paste according to any one of Embodiments 41 to 52, wherein the sulfonated polymer is according to any one of Embodiments 2 to 8, 13 to 14, or 18 to 24.

[0198] Embodiment 54. The electrode paste according to any one of Embodiments 41 to 53, wherein the salt of the sulfonated polymer is according to any one of Embodiments 9 to 12.

[0199] Embodiment 55. A method of manufacturing an electrode active layer, including:

[0200] applying the electrode paste according to any one of Embodiments 41 to 54 to a current collector; and

[0201] drying the electrode paste to remove the solvent.

[0202] Examples

[0203] The present invention will now be described with reference to the following examples, which should be considered illustrative and not restrictive in all respects.

[0204] The effective capacitance was calculated using Equation 1:

[0205]

[0206] Calculate the effective ESR using Equation 2:

[0207] Effective ESR (mΩ·cm 2 ) = ESR of the device (mΩ) × area of one active electrode (cm 2 ) … Equation 2

[0208] Example 1

[0209] Polystyrene sulfonic acid binder mixture (NaPSS-100)

[0210] Before physically coating on the aluminum foil using a K-bar, a doctor blade, or a slot die, water (3270 g), sodium polystyrene sulfonate (PSS; 46 g, MW = 1,000,000 g / mol, Sigma-Aldrich), carbon black (366 g), and activated carbon (1338 g) are mixed and suspended. According to the device specifications, the typical coating thickness applied is approximately 1 μm - 100 μm.

[0211] Test results and discussion

[0212] At a vacuum of less than 30 mbar and at 130 °C, a coating produced from the above binder mixture is applied to a thickness of ~50 μm, and the coated electrode forms a supercapacitor in a laminated package. The samples are tested in a test cell arrangement at 70 °C and 2.5 V.

[0213] Similar coatings prepared using CMC are also made in other identical supercapacitors. According to Table 1 below, compared with the CMC samples, the PSS samples show a significant reduction in the initial effective ESR and capacitance in terms of the effective ESR:

[0214]

[0215] The ESR and capacitance of the supercapacitor are tested by conventional discharge measurements (see Figure 1 and 2 ). As confirmed by these data, compared with using CMC, the ESR increase is much slower and the capacitance loss is slower when using PSS as the binder. The performance of the PSS capacitor after 600 hours is better than that of the CMC capacitor at 50 hours.

[0216] The PSS supercapacitor also shows an improved capacitance frequency response compared to other identical CMC supercapacitors (see Figure 3)。The PSS supercapacitor - 45° phase transition occurs at approximately 1.1 Hz compared to a similar CMC transition at 0.5 Hz (see Figure 4 ).

[0217] The PSS - coated supercapacitor also shows improved gas - exhaust performance relative to an otherwise identical CMC supercapacitor. Electrodes made with PSS or CMC as binders were assembled in a two - electrode configuration and charged to 2.5 V at 65 °C in a sealed laminated package. The laminated cell was placed between two flat plates, one plate fixed and the other able to slide on bearings. A load cell was placed on the freely - moving plate. Due to gas generation in the laminated package, the exhaust in the laminated cell was monitored by the force applied to the load cell, and the results are as Figure 5 shown. Less gas is generated in the cells of the supercapacitors using the PSS binder as judged by the force applied to the load cell at 100 h being lower than that of the equivalent CMC capacitor at 10 h.

[0218] The NaPSS binder is most effective at a pH close to 7.

[0219] Example 2

[0220] Polystyrene sulfonic acid binder mixture (NaPSS - 70)

[0221] Before physically coating on aluminum foil using a slot die, water (2250 g), sodium polystyrene sulfonate (PSS; 74.1 g, MW = 70,000 g / mol), carbon black (147 g), and activated carbon (526 g) were mixed and suspended. According to the equipment specifications, the typical coating thickness applied is approximately 1 μm - 100 μm.

[0222] Test results and discussion

[0223] The life tests of supercapacitors containing 70,000 g / mol PSS binder and 1,000,000 g / mol PSS binder are very similar and show a huge advantage over CMC supercapacitors in terms of both ESR rise rate and C - loss rate (see Figure 6 and Figure 7 ). The data consistency of different molecular weights of PSS indicates that the advantage of PSS is independent of the polymer molecular weight within this range.

[0224] Example 3

[0225] Polystyrene sulfonic acid binder mixture (X - PSS - 75)

[0226] As described below, electrode active layers were prepared using different PSS salt binders: Ca-PSS-75, Mg-PSS-75, Li-PSS-75, K-PSS-75, and Cs-PSS-75.

[0227] PSS (acid, 75,000 MW, 18% H2O solution) (7.52 g) was dissolved in deionized water (29.7 g) under magnetic stirring. The mixture was adjusted to pH 7 using Ca(OH)2 (saturated solution) and tetrafluoroboric acid. Methanol (0.83 g) was added and stirred for 10 min. Carbon black (2.72 g) was added and the mixture was stirred for 2 h. Activated carbon (9.45 g) was added and stirred overnight, and finally the mixture was dispersed for 1 min.

[0228] PSS (acid, 75,000 MW, 18% H2O solution) (3.82 g) was dissolved in deionized water (14.8 g) under magnetic stirring. The pH of the mixture was adjusted to 7 by adding Mg(OH)2 (about 0.14 g suspended in the least amount of water). Methanol (0.44 g) was added and stirred for 10 min. Carbon black (1.30 g) was added and the mixture was stirred for 2 h. Activated carbon (4.72 g) was added and stirred overnight, and finally the mixture was dispersed for 1 min.

[0229] PSS (acid, 75,000 MW, 18% H2O solution) (3.74 g) was diluted in deionized water (16.32 g) under magnetic stirring. The pH of the mixture was adjusted to 8 using LiOH (about 0.088 g dissolved in the least amount of water). Tetrafluoroboric acid (48% aqueous solution) was added dropwise to adjust the pH to 8. Methanol (0.41 g) was added and stirred for 10 min. Carbon black (1.29 g) was added and the mixture was stirred for 2 h. Activated carbon (4.65 g) was added and stirred overnight, and finally the mixture was dispersed for 1 min.

[0230] PSS (acid, 75,000 MW, 18% H2O solution) (3.76 g) was dissolved in deionized water (16.31 g) under magnetic stirring. The pH of the mixture was adjusted to 7 - 8 using KOH (about 0.21 g dissolved in the least amount of water) and tetrafluoroboric acid. Methanol (0.41 g) was added and stirred for 10 min. Carbon black (1.28 g) was added and the mixture was stirred for 2 h. Activated carbon (4.61 g) was added and stirred overnight, and finally the mixture was dispersed for 1 min.

[0231] Dissolve PSS (acid, 75,000 MW, 18% H2O solution) (3.75 g) in deionized water (16.59 g) using a magnetic stir bar. Adjust the pH of the mixture to 7 using CsOH (added in batches as a solid) and tetrafluoroboric acid. Add methanol (0.42 g) and stir for 10 min. Add carbon black (1.32 g) and stir the mixture for 2 hours. Add activated carbon (4.73 g) and stir overnight, and finally disperse the mixture for 1 minute.

[0232] Then physically coat each of the above mixtures on aluminum foil using a K bar. According to the device specifications, the typical coating thickness applied is approximately 1 μm - 100 μm.

[0233] Test Results and Discussion

[0234] The initial effective capacitance and ESR results for a series of metal cations including sodium, calcium, magnesium, potassium, cesium, and lithium are shown in Table 2 below:

[0235]

[0236] The ESR rise rate and C loss rate for the supercapacitor life test containing X-PSS-75 binder (X = K, Li, Cs, Mg, Ca) are as Figure 8-Figure 9 (Ca, Mg) and Figure 10-11 (Li, K, Cs) are shown.

[0237] The data in Table 2, Table 1, and Figure 1-Figure 11 show that Na, Li, Mg, and Ca are particularly suitable counterions for the PSS binder in supercapacitor devices with activated carbon as the active electrode material.

[0238] Example 3

[0239] Asymmetric / Hybrid Binder Devices

[0240] Construct capacitors using PSS as the binder (NaPSS-70) on the positive electrode and SBR as the binder (PSS-SBR) on the negative electrode, and vice versa (SBR-PSS).

[0241] Test Results and Discussion

[0242] Fig.12 and Fig.13 respectively show the C loss rate and ESR rise rate of the asymmetric device. Figure 14-17 The other data in

[0243] Example 4 show that PSS can be used alone or in combination with existing binders on the positive or negative electrode side with little adverse effect on the life or performance of the device.

[0244] Polystyrene sulfonic acid maleic anhydride copolymer binder mixture (NaPSS-coMA-20)

[0245] Sodium poly(4-styrenesulfonic acid-co-maleic acid) (20,000 MW, Sigma-Aldrich) (2.31 g) was dissolved in deionized water (50.12 g) under magnetic stirring. The mixture was stirred for 1 hour. Carbon black (9.74 g) was added and the mixture was mixed for 1 h and then dispersed in a high-shear mixer for 1 min. Activated carbon (20.24 g) was mixed and dispersed with the addition of water (12.58 g). These coatings were then applied using a 20 μm K-bar.

[0246] Test results and discussion

[0247] Final thickness: 33.6 ± 4.9 μm. Resistance: 6.53 mΩ. The system passed a 1000 h life test at 2.5 V. Sodium poly(4-styrenesulfonic acid-co-maleic acid) is a viable binder and the leakage results are consistent with existing PSS data.

[0248] It will be apparent to those skilled in the art that, although the present invention has been described in detail for purposes of clarity and understanding, various modifications and changes can be made to the embodiments and methods described herein without departing from the scope of the inventive concept disclosed in this specification.

Claims

1. An electrode active layer for an energy conversion or storage device, comprising: Active material; And A binder comprising a salt of a sulfonated polymer.

2. The electrode active layer according to claim 1, wherein The sulfonated polymer comprises substituted C2 to C6 linear or branched olefin monomers, optionally wherein the substituted C2 to C6 linear or branched olefin comprises one or more of the following as substituents: -R1SO3 - , -R1ArSO3 - , -ArR1SO3 - , -ArSO3 - or -C(=O)NHR1SO3 - , -C(=O)NHR1ArSO3 - , -C(=O)NHArR1SO3 - ; Wherein R1 = C1 to C6 linear or branched alkyl or a bond; and Ar = aryl, optionally phenyl.

3. The electrode active layer according to claim 1 or 2, wherein The sulfonated polymer comprises a benzenesulfonic acid group.

4. The electrode active layer according to any one of the preceding claims, wherein, The sulfonated polymer comprises monomers, each of the monomers comprising a sulfonic acid group, optionally each of the monomers comprising a benzenesulfonic acid group.

5. The electrode active layer according to any one of the preceding claims, wherein, The sulfonated polymer comprises one or more monomers selected from the following: styrenesulfonic acid, vinylsulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, 2-propene-1-sulfonic acid or 2-methyl-2-propene-1-sulfonic acid, optionally styrenesulfonic acid.

6. The electrode active layer according to any one of the preceding claims, wherein, The salt of the sulfonated polymer comprises one or more counterions selected from the following: Group I metal cations, Group II metal cations, transition metal cations, quaternary ammonium cations or nitrogen-containing heterocyclic cations.

7. The electrode active layer according to any one of the foregoing claims, wherein, The salt of the sulfonated polymer comprises one or more counterions selected from the following: Lithium cation, potassium cation, sodium cation, cesium cation, magnesium cation and calcium cation.

8. The electrode active layer according to any one of the preceding claims, wherein, The salt of the sulfonated polymer comprises one or more counterions selected from the following: optionally substituted alkylammonium cations such as tetramethylammonium, tetraethylammonium, tetrapropylammonium or tetrabutylammonium or 2-(methylthio)ethylammonium cation; or nitrogen-containing heterocyclic cations such as spiro-bis-pyrrolidinium (SBP), N,N-dimethylpyrrolidinium, N-methyl-N'-propylpyrrolidinium, N,N'-dimethylimidazolium, N-methyl-N'-ethylimidazolium or N-methyl-N'-propylimidazolium.

9. The electrode active layer according to any one of the preceding claims, wherein, The sulfonated polymer has an average molecular weight of about 20,000 g / mol to about 2,000,000 g / mol, optionally about 20,000 g / mol to about 1,000,000 g / mol.

10. The electrode active layer according to any one of the preceding claims, wherein, The binder comprises at least 30 wt% of the salt of the sulfonated polymer, optionally at least 50 wt% of the salt of the sulfonated polymer, or optionally at least 90 wt% of the salt of the sulfonated polymer.

11. The electrode active layer according to any one of the preceding claims, wherein, The sulfonic acid polymer is a copolymer comprising two or more different sulfonated monomers.

12. The electrode active layer according to any one of the preceding claims, wherein, The sulfonic acid polymer is a copolymer comprising one or more sulfonated monomers and at least one other monomer, Wherein each of the sulfonated monomers comprises a sulfonic acid group, optionally each of the sulfonated monomers comprises a benzenesulfonic acid group, and Wherein the at least one other monomer has no sulfonic acid group, optionally wherein the at least one other monomer is selected from one or more of the following: 1,2-difluoroethylene, tetrafluoroethylene, styrene, butadiene, maleic anhydride, maleic acid or its salt, acrylic acid or its salt, methacrylic acid or its salt, or butylacrylic acid or its salt.

13. The electrode active layer according to any one of the preceding claims, wherein, The binder comprises a mixture of salts of two or more different sulfonated polymers, or a mixture of a salt of a sulfonated polymer and at least one other polymer, optionally wherein the other polymer is selected from PVDF, PTFE, SBR or an acrylic-based polymer.

14. The electrode active layer according to any one of the preceding claims, wherein, The active material is amorphous carbon, optionally activated carbon.

15. The electrode active layer according to any one of the preceding claims further comprises a conductive material, optionally conductive carbon.

16. A composite electrode comprising: The electrode active layer according to any one of claims 1 to 15 on a conductive surface.

17. An energy storage device comprising the composite electrode according to claim 22.

18. The energy storage device according to claim 17, wherein the energy storage device is a supercapacitor or a battery.

19. Use of a salt of a sulfonated polymer as an adhesive in the electrode active layer of a composite electrode.

20. An electrode paste for producing an electrode active layer, the electrode paste comprising: Active material; An adhesive comprising a salt of a sulfonated polymer; And A solvent.

21. The electrode paste according to claim 20, comprising 50 wt% to 95 wt% of a solvent, optionally wherein, The solvent is water.

22. The electrode paste according to claim 20 or 21, comprising 1 wt% to 30 wt%, optionally 2 wt% to 20 wt%, of the adhesive based on solids.

23. The electrode paste according to any one of claims 20 to 22, wherein, The paste is a substantially homogeneous dispersion of the active material.

24. A method of manufacturing an electrode active layer, comprising: Applying the electrode paste according to any one of claims 20 to 23 to a current collector; And Drying the electrode paste to remove the solvent.

Images